Not ACH, but the ACATS system (transfer securities between brokerages) has recently seen a number of thefts. It seems like a horribly insecure system. If a sca

Not ACH, but the ACATS system (transfer securities between brokerages) has recently seen a number of thefts. It seems like a horribly insecure system. If a scammer knows you own stocks, and can impersonate you, they can set up an account at another brokerage and pull your stocks away with ACATS. YOUR brokerage is required to send them, and does no verification. You probably won't even get a notification. https://www.bogleheads.org/forum/viewtopic.php?p=6756853 https://www.bogleheads.org/forum/viewtopic.php?p=6756853 Fidelity seems to be the only brokerage at the moment that lets you "lock down" your account and prohibit outbound transfers.